KR20150026779A - Photomask for manufacturing display device, method for manufacturing photomask, pattern transfer method and method for manufacturing display device - Google Patents

Abstract

The purpose of the present invention is to provide a photomask for manufacturing a display device improving the transcription of a micro-pattern. The photomask for manufacturing a display device is manufactured by forming a pattern for transcription including a the light-shielding part, a phase shift part and a light transmission part by patterning a phase shift film, an etching mask film and a light-shielding film on a transparent substrate by each wet etching. The light-shielding part is formed by laminating the phase shift film, the etching mask film and the light-shielding film in order. The phase shift part is the phase shift film or is formed by laminating the phase shift film and the etching mask film. The light transmission part is formed by exposing the surface of the transparent substrate. The phase shift film is made up of materials containing chrome. The etching mask film is made up of materials having etching resistance on the etching of the phase shift film. The phase shift part and the light transmission part have a part adjacent to each other. The phase shift part and the light transmission part have a phase difference of about 180 degrees on representive wavelength of the exposure light of the photomask.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomask for manufacturing a display device, a method of manufacturing the photomask, a method of transferring a pattern, and a manufacturing method of a display device. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a photomask for manufacturing a display device capable of forming a fine pattern in the manufacture of a display device, a method of manufacturing the photomask, a pattern transfer method using the photomask, and a method of manufacturing the display device.

Patent Document 1 discloses an invention relating to a method of manufacturing a phase shift mask capable of forming fine and highly accurate exposure patterns. In this document, it is described that the glass substrate for a flat panel is of a size exceeding 300 mm, and therefore, the substrate is bent and the surface roughness becomes large, and is easily affected by the depth of focus.

Therefore, in Patent Document 1, it is possible to pattern the light shielding layer on the transparent substrate and sputter the target of the chromium-based material to have a phase difference of 180 DEG with respect to any light in the wavelength range of 300 nm to 500 nm Discloses a method of manufacturing a phase shift mask in which a phase shift layer is formed on the transparent substrate so as to cover the light shielding layer and the phase shift layer is patterned.

Patent Document 2 discloses a photomask for manufacturing an FPD (Flat Panel Display) having a shielding region and a light-transmitting region in a blind region and a phase inversion region and a light-transmitting region in a main region, Wherein the transparent region of the blind region comprises the transparent substrate region in which the phase reversal film and the light shielding film pattern are sequentially etched and exposed, And the transparent substrate region exposed by etching the phase reversal film stacked on the transparent substrate region, wherein the etching rate of the light-shielding film pattern is higher than the etching rate of the phase reversal film for the same etching substance .

[Patent Document 1] Japanese Unexamined Patent Publication No. 2011-13283 [Patent Document 2] Japanese Unexamined Patent Publication No. 230309/1989

At present, VA (Vertical Alignment) method or IPS (In Plane Switching) method is adopted for a liquid crystal display device. With these applications, improvement in display performance such as high-precision, high-speed display, and wide viewing angle has been demanded, while being brighter and saving power.

For example, in a liquid crystal display device to which these methods are applied, a transparent conductive film formed in a line-and-space pattern shape is applied to the pixel electrode, and in order to improve the display performance of the liquid crystal display device, . For example, it is desired to narrow the pitch width P (sum of the line width L and the space width S) of the line and space pattern from 6 mu m to 5 mu m, and further to 5 mu m to 4 mu m. In this case, at least one of the line width L and the space width S is often less than 3 mu m. For example, L <3 탆 or L ≤ 2 탆, or S <3 탆 or S ≤ 2 탆 in many cases.

On the other hand, in the case of a thin film transistor ("TFT") used in a liquid crystal display device or an EL (electroluminescence) display device, among a plurality of patterns constituting TFTs, a contact formed with a passivation layer A configuration in which the hole traverses the insulating layer and is conducted to the connection portion on the lower layer side is adopted. At this time, if the patterns on the upper layer side and the lower layer side are accurately positioned and the shape of the contact hole is not reliably formed, the correct operation of the display device is not guaranteed. Also here, along with the improvement of the display performance, high integration of the device pattern is required, and the pattern is required to be miniaturized. That is, it is required that the diameter of the hole pattern is less than 3 占 퐉. For example, it is considered that a hole pattern having a diameter of not more than 2.5 mu m, and furthermore, a diameter of not more than 2.0 mu m is required, and formation of a pattern having a diameter of not more than 1.5 mu m short of this pattern is desired.

From such a background, there is a demand for a photomask for manufacturing a display device capable of coping with line and space patterns and miniaturization of contact holes.

In the field of photomasks for manufacturing semiconductors (LSIs, etc.), in order to obtain resolution, a process of developing a phase shift mask using a phase shift action together with an optical system of a high NA (Numerical Aperture) . The phase shift mask is used together with a light source (such as KrF or ArF excimer laser) having a single wavelength and a short wavelength. As a result, high integration of various devices and the like and miniaturization of the pattern of the photomask accompanying thereto have been addressed.

On the other hand, in the field of lithography for manufacturing display devices, it has not been general that the above-described method is applied to improve the resolution and the depth of focus. For this reason, it is exemplified that the degree of integration and fineness of the pattern, which are required in the display device, were not in the field of semiconductor manufacturing. Actually, an optical system and a light source mounted on an exposure apparatus (generally known as an LCD (Liquid Crystal Display) exposure apparatus or a liquid crystal exposure apparatus, etc.) for producing display devices are also different from those for semiconductor manufacturing, Production efficiency (for example, by enlarging the wavelength range of the light source to obtain a large irradiated light quantity, shortening the production tact, etc.) has been emphasized.

When the transfer pattern of the photomask becomes finer, it becomes difficult to carry out the step of accurately transferring the transferred pattern onto a transfer target body (also referred to as a thin film to be etched or a workpiece). Although the resolution limit of the above-described exposure apparatus, which is practically used in the transfer process in the manufacture of the display apparatus, is about 3 mu m, among the transfer patterns necessary for the display apparatus, the CD (Critical Dimension) , It is necessary to have a dimension which is already close to or below this dimension.

In addition, since the mask for manufacturing a display device has a larger area than a mask for manufacturing a semiconductor, there is a great difficulty in uniformly transferring a transfer pattern having a CD of less than 3 mu m in the plane of production.

As described above, in the case of using a mask for manufacturing a conventional display device, transfer of a fine pattern such as a CD having a size of less than 3 mu m is difficult, and thus various methods for improving the resolution, It is considered to be applied to the field of display device manufacturing.

However, there are several problems in applying the above-described method directly to the manufacture of display devices. For example, a large investment is required for switching to a high-resolution exposure apparatus having a high NA (numerical aperture), and inconsistency arises in the consistency with the display device. Alternatively, it is difficult to apply to a display device having a relatively large area for changing the exposure wavelength (using a single wavelength such as an ArF excimer laser for a single wavelength), and besides the problem that the manufacturing tact is liable to be prolonged, It is unsuitable for what it needs.

Therefore, it is very significant if the transferability of the fine pattern can be improved by designing the transfer pattern provided in the photomask for manufacturing a display device.

The gist of the present invention is as follows.

A photomask for manufacturing a display device in which a transfer pattern including a light-shielding portion, a phase shifting portion, and a light-transmitting portion is formed by patterning a phase shift film, an etching mask film, and a light- as,

Wherein the shielding portion is formed by laminating the phase shift film, the etching mask film, and the light shielding film in this order on the transparent substrate,

Wherein the phase shifting portion is formed by forming the phase shift film or the phase shift film and the etching mask film on the transparent substrate,

Wherein the transparent portion is formed by exposing the surface of the transparent substrate,

Wherein the phase shift film is made of a material containing chromium,

The etching mask film is made of a material having an etching resistance to the etching liquid of the phase shift film,

Wherein the phase shifting portion and the light transmitting portion have portions adjacent to each other and the phase shifting portion and the light transmitting portion have a phase difference of about 180 degrees with respect to a representative wavelength of exposure light of the photomask.

Photomask for manufacturing display devices.

The transfer pattern includes a line-and-space pattern, and the line pattern of the line-and-space pattern has a light-shielding portion having a constant width and a phase shift portion having a constant width adjacent to both sides of the light- The photomask for manufacturing a display device according to < 1 >

The transfer pattern includes a hole pattern, the hole pattern has a transparent portion having a predetermined diameter, a phase shift portion having a constant width surrounding the transparent portion, and a shielding portion surrounding the phase shift portion To (4).

It is preferable that the phase shifting portion has the phase shift film formed on the transparent substrate and the phase shift film is phase shifted by about 180 degrees with respect to the representative wavelength of the exposure light. To < 3 >.

The phase shifting portion may include a transparent substrate on which the phase shift film and the etching mask film are stacked in this order,

The display device manufacturing port according to any one of < 1 > to < 3 >, characterized in that the lamination of the phase shift film and the etching mask film is phase shifted approximately 180 degrees with respect to a representative wavelength of the exposure light. Mask.

<6> A surface to be etched of the phase shift film is exposed at a portion of the transfer pattern adjacent to the transparent portion and the phase shift portion,

The upper side, the lower side and the side face corresponding to the upper face, lower face and etched face of the phase shift film satisfy the following conditions (A) and (B), respectively, Gt; a < / RTI > photomask for manufacturing a display device according to any one of <

(A) a straight line connecting a contact point of the upper side and the side face and a position of the side face at a position of a height of two thirds lower than the film thickness of the phase shift film from the upper face, It is within a range of 120 degrees from the road,

(B) a first imaginary line which is perpendicular to the main surface of the transparent substrate through the upper side and the side edge of the side face, and a position of the side edge at a position which is one tenth the height of the film thickness from the bottom face And a second imaginary line perpendicular to the main surface of the transparent substrate is equal to or smaller than half of the film thickness.

A photomask for manufacturing a display device in which a transfer pattern including a light-shielding portion, a phase shifting portion, and a light-transmitting portion is formed by patterning a phase shift film, an etching mask film, and a light- A process for producing

Wherein the shielding portion is formed by laminating the phase shift film, the etching mask film, and the light shielding film in this order on the transparent substrate,

Wherein the phase shifting portion is formed by forming the phase shift film or the phase shift film and the etching mask film on the transparent substrate,

Wherein the transparent portion of the transparent substrate is exposed, the method comprising the steps of:

A step of preparing a photomask blank on which a phase shift film, an etching mask film, and a light shielding film are stacked in this order and on which a first photoresist film is formed,

A step of forming a transfer pattern by subjecting the phase shift film, the etching mask film and the light shielding film to predetermined patterning,

The step of patterning the phase shift film includes wet etching the phase shift film using the patterned etching mask film as a mask,

Wherein the phase shift film is made of a material containing chromium,

The etching mask film is made of a material having an etching resistance to the etching liquid of the phase shift film,

The phase shifting section and the transmissive section have portions adjacent to each other and the phase shifting section and the transmissive section have a phase difference of about 180 degrees with respect to a representative wavelength of the exposure light of the photomask doing,

A method of manufacturing a photomask for manufacturing a display device.

<8> A method for manufacturing a display device, comprising the steps of: preparing a photomask for manufacturing a display device according to any one of <1> to <3>

a transferring pattern of the photomask is exposed using an exposure apparatus for manufacturing a display device which irradiates exposure light including i line, h line and g line, and the transfer pattern is transferred onto a transfer target body And transferring the pattern onto the recording medium.

<9> A method of manufacturing a display device, comprising the steps of: preparing a photomask for manufacturing a display device according to any one of <1> to <3>

a transferring pattern of the photomask is exposed using an exposure apparatus for manufacturing a display device which irradiates exposure light including i line, h line and g line, and the transfer pattern is transferred onto a transfer target body The method comprising the steps of:

According to the present invention, there is provided a photomask for manufacturing a display device capable of forming a fine pattern as designed in the manufacture of a display device, a method of manufacturing the photomask, a pattern transfer method using the photomask, and a method of manufacturing the display device do.

1 is a schematic view of a phase shift mask of a line-and-space pattern on a top surface (top view) in the simulation of the difference in phase shift effect due to the difference in sectional shape of the phase shift film pattern 1 (c) of a phase shift mask of a partial cross-sectional view (FIG. 1 (b)) and other shapes of a portion thereof, and a cross-sectional view of a binary mask )]to be.
Fig. 2 is a view showing a light intensity distribution curve formed on a body to be exposed when exposure is performed using three types of photomasks used in the simulation. Fig.
3 is a schematic cross-sectional view of a photomask blank prepared in the production of the photomask of the present invention.
4 is a cross-sectional view (lower side) and a corresponding upper surface trial (upper side) of the photomask (FIG. 4A) of the present invention according to the first embodiment and the photomask of the present invention (lower side) and the corresponding upper surface try (upper side) of Fig.
5 shows a photomask of the present invention (Fig. 5 (a)) according to the first embodiment and a photomask according to the second embodiment (Fig. 5 (b) And FIG.
6 is a view for explaining a shape of the etched surface (side) of the patterned phase shift film.
7 is a view showing an example of a method of manufacturing a photomask according to the first and second embodiments of the present invention.
8 is a view showing an example of a method of manufacturing a photomask according to the first and second embodiments of the present invention.
9 is a diagram showing an example of a method of manufacturing the photomask of the first embodiment using side etching.
10 is a reference view showing a cross section of a phase shift film pattern to be obtained when wet etching is performed using a resist pattern as a mask.

In the photolithography process, in order to reliably transfer a fine pattern, the light intensity distribution imparted to the resist film on the transferred body becomes important by an exposure process using a photomask. That is, when the contrast of the light intensity distribution curve is high and the profile of the resist pattern formed on the transfer body is improved, etching processing of a transfer destination body such as a display device substrate can be performed more precisely and densely have. In the case of a photomask for a display device, generally, the area is large (at least 300 mm on one side), patterning can be performed uniformly throughout the entire surface, and uniformity of CD in the surface can be controlled Since it is important, the shape of the light intensity distribution curve formed by the exposure light is particularly important.

However, in the above Patent Documents 1 and 2, it is described that a photomask having a phase shift layer (or a phase inversion layer) is used in order to perform fine or highly accurate pattern formation or to obtain a high resolution .

According to Patent Document 1, a phase-shift layer of a chromium-based material is formed on a transparent substrate by forming a light-shielding film with a chromium-based material, etching the light-shielding film into a predetermined shape, The phase shift layer is patterned using the resist pattern formed by the photoresist as a mask. Also. Also in Patent Document 2, a photomask is formed by etching a phase reversal film containing chromium formed on a light-shielding film pattern containing chromium.

Here, when the phase shift layer (or the phase reversal film) is etched using the resist pattern as a mask, it is expected that the phase shift film is faithfully patterned for the resist pattern. However, it has been discovered by the present inventors that wet etching is applied to the following problems.

For example, in a case where wet etching is performed using a resist pattern as a mask in order to perform desired patterning on a phase shift film containing chromium (hereinafter also referred to as a chromium phase shift film), a cross section of the resulting phase shift film pattern Is shown in Fig. 10 is a view showing a cross section of a phase shift film pattern 102 obtained by etching a phase shift film made of CrOCN formed on a transparent glass substrate 101 with a resist pattern 103 of a positive type photoresist as a mask to be.

10, the cross section of the phase shift film (PS film) pattern 102 in contact with the etchant is not perpendicular to the surface of the transparent glass substrate 101, (Hereinafter also referred to as &quot; shape &quot;). This is because the adhesion of the interface between the phase shift film pattern 102 and the resist pattern 103 is insufficient and the etchant penetrates into the resist film 103 from the upper surface side of the film to a larger extent than the lower surface side (glass substrate side) Etching in the right direction) is progressed.

For the purpose of increasing the contrast of the transfer image and improving the depth of focus by utilizing the phase inversion of the transmitted light at the boundary between the transparent portion through which the exposure light is transmitted and the light shielding portion through which the exposure portion shields light, The mask (phase shift mask) is mainly used in the field of semiconductor manufacturing. It is known that these phase shift masks use a phase shift film having a transmittance of about 5 to 10% for the exposure light (for example, KrF or ArF excimer laser) and shifting the phase of the exposure light by about 180 degrees.

However, since the photomask (phase shift mask) used in the above-mentioned fields is generally manufactured by applying dry etching, there has never been a problem caused by employing the wet etching. However, as described above, the photomask for manufacturing a display device has a relatively large size (a rectangular substrate having 300 mm or more on one side (usually, 1800 mm or less) is used) and the size is various , It is advantageous to apply wet etching rather than dry etching.

On the other hand, in a photomask for manufacturing a display device, a multi-gradation photomask having a transfer pattern including a semi-light-transmitting portion, which partially transmits exposure light, is used in addition to a light-shielding portion and a light- In this photomask, the light transmittance of the transparent portion, the light shielding portion, and the translucent portion is made different from each other (the light transmittance of the light shielding portion is substantially zero), thereby forming a three-dimensional step By using this, it is possible to reduce the number of steps in processing the transferred body.

The semi-light-transmitting portion in the multi-gradation photomask may be formed by forming a semi-light-transmitting film (a film having a transmittance that passes through about 20 to 80% of exposure light) on a transparent substrate.

However, at the time of manufacturing such a multi-gradation photomask, the phase difference of the exposure light transmitted through each of the boundaries between the translucent portion and the transparent portion was not set to about 180 degrees. If the phase difference between the exposure light transmitted through the translucent portion and the exposure light transmitted through the transparent portion is close to 180 degrees, a substantially light-shielding line pattern is formed at the boundary between the translucent portion and the translucent portion, A problem arises that a three-dimensional shape can not be obtained.

That is, in the photomask for manufacturing a display device, the problem that the cross section of the semi-light-transmitting film is inclined with respect to the substrate surface has not been conventionally present.

The inventors of the present invention conducted simulation on how the etched end face of the phase shift film in the photomask is not perpendicular to the surface of the substrate but has an inclined cross-sectional shape to affect the transferability of the photomask. That is, in the transfer pattern of the photomask, the phase shift effect obtained by reversing the phases of the exposure light transmitted through the respective boundaries between the transparent portion and the phase shift portion is caused by the etched cross-sectional shape of the phase shift film, And whether it will change.

<Simulation Results>

Before explaining the embodiment of the present invention, the difference in the phase shift effect due to the difference in cross-sectional shape of the phase shift film pattern will be described using the results of the above simulation.

The simulation was performed by applying the optical conditions of the exposure apparatus for manufacturing a display device. (Intensity ratio: g-line: h-line: i-line) having a numerical aperture (NA) of the optical system of 0.085, a coherence factor sigma of 0.9 and exposure light including g- = 0.95: 0.8: 1.0).

In this simulation,

A phase shift mask PSM (A) having a phase shift film pattern in which the cross-sectional shape of the edge portion is perpendicular to the substrate surface,

(PSMTP (A)) obtained by modeling the phase shift film pattern of Fig. 10 in which the edge shape of the edge portion is tapered, and

Binary Mask (Bin)

. Figs. 1 (b) to 1 (d) show a schematic view of each mask section.

1 (a) is a schematic view of a line-and-space pattern used in the simulation on the upper surface, and shows a part of the line-and-space pattern in the PSM (A). Fig. 1 (b) is a view showing a partial cross section of the phase shift mask having the line and space pattern.

1 (b), the phase shift mask PSM (A) has a phase shift film pattern 12a formed on a transparent substrate 11, an etching mask film pattern 13a formed thereon, And a light-shielding film pattern 14a is formed thereon. The portion of the light-shielding film pattern 14a in this top view (i.e., Fig. 1A) is the light-shielding portion 15 and the portion of the phase shift film pattern 12a that is not covered with the light- The exposed portion is the phase shift portion 16 and the exposed portion of the transparent substrate 11 on which nothing is laminated constitutes the transparent portion 17.

The phase shift mask PSM (A) is made of a line and space pattern having a line width L of 2.0 mu m and a space width S of 2.0 mu m (pitch P of 4.0 mu m), and the line pattern 2a has a width of 1.0 mu m And the phase shifting portions 16 each having a width of 0.5 mu m are provided at the edges of both sides of the light-shielding portion 15. [ The same applies to the line patterns 2b and 2c. The space patterns 3a, 3b and 3c are transparent portions 17 in which the transparent substrate 11 is exposed.

The light shielding portion 15 is a portion where at least a light shielding film pattern 14a is formed on the transparent substrate 11 and the exposure light transmittance is substantially zero. The phase shift portion 16 is formed on the portion of the phase shift film pattern 12a having the light transmittance of 6% (twin i-line) formed (the portion covered with the light shield film pattern 14a) ). The phase difference between the phase shifting portion 16 and the light projecting portion 17 with respect to the exposure light is 180 degrees (pair i-line).

Next, the phase shift mask PSMTP (A) shown in Fig. 1 (c) also has a line-and-space pattern with a line width L of 2.0 m and a space width S of 2.0 m, And the phase shifting portions each having a width of 0.5 mu m are provided at the edges of both sides of the light shielding portion. The space pattern is made up of a transparent portion in which the transparent substrate is exposed. Note that the phase shifting portion is formed such that the film thickness of the phase shift film formed on the transparent substrate gradually decreases in 10 steps from the light shielding portion side toward the light transmitting portion side (in the width direction of the line pattern). In other words, in the phase shifting portion, the portion close to the light shielding portion among other things has an exposure light transmittance of 6% (pair i-line) and a phase difference of 180 degrees with respect to the light transmitting portion (pair i-line) The portion near the transparent portion has an exposure light transmittance of 57.5% (a pair i-line) and a retardation (a pair i-line) with the transparent portion is 20.19 degrees.

1 (d) is a line and space pattern having a line width L of 2.0 m and a space width S of 2.0 m, and the line portion is formed by forming a light shielding film on the transparent substrate Shielding portion, and the light-transmitting portion is composed of a portion where the surface of the transparent substrate is exposed.

2 is a graph showing the relationship between the light intensity distribution curve formed on the transferred body when exposed using the phase shift mask PSM (A), the phase shift mask PSMTP (A), and the binary mask Bin Respectively. In Fig. 2, the center of the line pattern 2a is set to the zero position, and the light intensity is 1.0 when the exposure light transmittance is 100%. When the maximum value (maximum light intensity) of the light intensity distribution curve is Imax and the minimum value (minimum light intensity) is Imin, the contrast can be calculated as (Imax-Imin) / (Imax + Imin).

Table 1 below shows numerical values of maximum light intensity Imax, minimum light intensity Imin, and contrast for each mask of PSM (A), PSMTP (A), and Bin.

From this result, in the phase shift mask PSM (A) in which no taper is formed on the edge surface of the phase shift film pattern (the cross section is perpendicular to the substrate surface), the edge section of the phase shift film pattern is tapered The contrast is higher than in the case of the phase shift mask [PSMTP (A)] or the binary mask Bin.

As shown in Table 1, the contrast when the phase shift mask PSM (A) is used is 0.67273, but according to the examination by the present inventors, it is preferable that a contrast of 0.65 or more is obtained. It is also preferable that a value of 0.1 or less is obtained as the minimum value Imin of the light intensity.

Further, the contrast of the phase shift mask PSMTP (A) is lower than that of the binary mask Bin. Since the edge portion of the phase shift film pattern is tapered, the phase shift mask [PSMTP (A)] has a high transmittance and a small phase difference with the transparent portion as it approaches the transparent portion. As a result, it can be seen that the effect of improving the contrast due to the optical interference of the inverted phase is reduced at the boundary between the phase shifting portion and the light transmitting portion.

This means that the contrast of the light intensity distribution formed on the transferred body is deteriorated, that is, the profile (resist cross-sectional shape) of the resist pattern formed thereon is deteriorated.

As described above, it can be seen that the effect of improving the contrast due to the optical interference of the inverted phase at the boundary between the transparent portion and the phase shifting portion is improved by making the end face of the edge portion of the phase shift film pattern closer to the substrate surface have.

Next, a method of suppressing the inclination of the edge of the phase shift film pattern at the boundary between the phase shifting portion and the light transmitting portion was studied.

The penetration of the etching liquid into the wet etching at the interface between the resist film (formed of the photosensitive resin composition) and the chromium phase shift film is caused by the insufficient adhesion between the chromium phase shift film and the resist film. This deteriorates the light intensity contrast of the portion of the phase shift film pattern to be etched (tilts), and makes it difficult to control the CD (line width) of the phase shift portion .

In other words, it is also possible to improve the CD accuracy of the pattern by improving the etched cross-sectional shape of the phase shift film pattern. This makes it possible to produce a photomask for a display device capable of transferring a fine pattern, and a display device manufactured using the same can contribute to a stable high yield.

[Photomask for manufacturing display device of the present invention]

A photomask for manufacturing a display device according to the present invention (hereinafter, also referred to as a photomask of the present invention)

1. A photomask for manufacturing a display device in which a transfer pattern including a light-shielding portion, a phase shifting portion, and a light-transmitting portion is formed by patterning a phase shift film, an etching mask film, and a light-

Wherein the shielding portion is formed by laminating the phase shift film, the etching mask film, and the light shielding film in this order on the transparent substrate,

Wherein the phase shifting portion is formed by forming the phase shift film or the phase shift film and the etching mask film on the transparent substrate,

Wherein the transparent portion is formed by exposing the surface of the transparent substrate,

Wherein the phase shift film is made of a material containing chromium,

The etching mask film is made of a material having an etching resistance to the etching liquid of the phase shift film,

The phase shifting portion and the light transmitting portion have portions adjacent to each other and the phase shifting portion and the light transmitting portion have a phase difference of about 180 degrees with respect to the representative wavelength of the exposure light of the photomask.

3, a photomask blank in which a phase shift film 12, an etching mask film 13, and a light shielding film 14 are formed in this order is prepared on a transparent substrate 11 And can be manufactured using this. However, another film may be interposed between these films or between any one of the films and the transparent substrate 11 within the range not hindering the effect of the present invention.

In the photomask of the present invention, the phase shift film 12, the etching mask film 13 and the light shield film 14 are patterned by wet etching based on a predetermined pattern design on the transparent substrate 11, And has a transfer pattern formed thereon.

A typical configuration of the photomask of the present invention is the phase shift mask PSM (A) shown in Fig. 1 (b) used in the simulation described above (Fig. 1 (b) As shown in FIG.

The laminated portion of the light-shielding film pattern 14a and the corresponding etching mask film pattern 13a and the phase shift film pattern 12a on the top face of this photomask (Fig. 1 (a) ).

The portion of the phase shift film pattern 12a that is not covered with the light-shielding film pattern 14a and is exposed (the portion where the phase shift film pattern 12a is seen from the top face) .

The exposed portion of the transparent substrate 11 (the portion where the transparent substrate 11 is seen from the top surface) constitutes the transparent portion 17. The transparent portion 17 and the phase shifting portion 16 have portions adjacent to each other.

The exposure light transmitted through the phase shifting portion 16 is shifted in phase by 180 degrees with respect to the exposure light transmitted through the light transmitting portion and interferes with the exposure light transmitted through the light transmitting portion 17 and the adjacent portion . As a result, the optical contrast of the portion is improved, and the edge shape of the intensity curve of the exposure light becomes sharper. Therefore, the photomask of the present invention can also cope with a minute pattern in manufacturing a display device which is recently required.

Such a photomask of the present invention is not particularly limited as long as it has the above configuration, but a typical embodiment of the photomask of the present invention will be described below.

<First Photo Mask>

Sectional view of the photomask according to the first embodiment of the present invention is shown in the lower part of Fig. The photomask 10a includes a phase shift film 12, an etching mask film 13, a light shielding film 14, a first photoresist film (for example, 18 can be formed in this order by preparing a photomask blank and patterning the phase shift film 12, the etching mask film 13, and the light shield film 14.

In this photomask 10a,

The phase shifting film 12, the etching mask film 13 and the light shielding film 14 are patterned by wet etching on the transparent substrate 11 so that the light shielding portion 15, the phase shifting portion 16, A photomask (10a) for manufacturing a display device in which a transfer pattern including a light portion (17) is formed,

The shielding part 15 is formed by laminating the phase shift film 12, the etching mask film 13 and the light shielding film 14 in this order on the transparent substrate,

The phase shift portion (16) is formed by forming the phase shift film (12) on the transparent substrate,

The transparent portion 17 is formed by exposing the surface of the transparent substrate 11,

The phase shift film 12 is made of a material containing chromium,

The etching mask film 13 is made of a material having etching resistance to the etching liquid of the phase shift film 12,

The phase shifting section 16 and the light projecting section 17 are arranged in the same direction as the phase shifting section 16 and the light projecting section 17, And has a phase difference of about 180 degrees with respect to the representative wavelength.

4A is an upper surface of the first photomask 10a and the patterned shielding film 14 (that is, the light-shielding film pattern 14a) in the case of viewing the photomask 10a from above The portion where the visible portion constitutes the light shielding portion 15 and the portion where the patterned phase shift film 12 (i.e., the phase shift film pattern 12a) is visible constitutes the phase shift portion 16 and the transparent substrate 11 The portions that are not covered with any of the phase shift film 12, the etching mask film 13 and the light shielding film 14 to form the transparent portion 17 are exposed.

The structure of the first photomask 10a can be configured as follows.

[Transparent Substrate (11)]

The material of the transparent substrate 11 is not particularly limited as long as it is a material having translucency to the exposure light to be used. Examples of the material of the transparent substrate 11 include synthetic quartz glass, soda lime glass, and alkali-free glass.

[Phase shift film 12]

The phase shift film 12 in the present invention is a semi-transmissive film because a part of the exposure light is transmitted. The phase shift film 12 also has the function of shifting the phase of the exposure light by a predetermined amount.

The phase shift film 12 in the present invention is made of a material containing chromium. The phase shift film 12 is formed of a material such as CrOx, CrNx, CrCx, CrOxNy, CrCxNy, CrOxCy, CrOxNyCz), and chromium fluoride (CrFx).

The phase shift film 12 is preferably made of a chromium-containing film having chromium of less than 50 atomic% in order to obtain an optical property described later.

The film thickness of the phase shift film is preferably 800 to 1800 angstroms.

For the wet etching of the phase shift film 12, a known etchant can be used. For example, a mixed aqueous solution of ammonium ceric nitrate and perchloric acid can be used.

In the first photomask 10a, the exposure light transmittance of the phase shift film 12 may be 2 to 15%, and more preferably 3 to 8%. Here, the exposure light is a light source generally employed in an LCD exposure apparatus, and light including any one of i-line, h-line, and g-line can be used, and more preferably, light including both of them is used . In the present application, the transmittance and the phase difference (or the phase shift amount) are defined as the exposure light transmittance, with either one of the above wavelengths being a representative wavelength.

In the first photomask 10a, the phase shift amount of the exposure light (i-line as a representative wavelength) of the phase shift film 12 is approximately 180 degrees. Here, the angle may be approximately 180 degrees, 160 to 200 degrees, and preferably 170 to 190 degrees.

In the exposure light having a wavelength of 365 nm (i line) to 436 nm (g line), the variation width of the phase shift amount is preferably within 40 degrees, more preferably within 30 degrees. When the fluctuation width is in this range, the effect of substantially 180 degrees of the phase shift amount of the exposure light of the representative wavelength is obtained.

[Etching mask film 13]

It is essential that the etching mask film 13 in the present invention is formed of a material having high adhesion to the phase shift film 12 and a material having etching selectivity with respect to the phase shift film 12. That is, the etching mask film 13 has etching resistance to the etching liquid of the phase shift film 12.

Examples of the material of the etching mask film 13 in the present invention include aluminum (Al), cobalt (Co), tungsten (W), molybdenum (Mo), vanadium (V), titanium Mn, iron, nickel, zirconium, magnesium, copper, yttrium, sulfur, indium, tin, tantalum, Ta, hafnium (Hf), niobium (Nb), and silicon (Si).

Specific examples of the material include nitrides, oxides, carbides, oxynitrides, carbonitrides, oxycarbides, and oxycarbonitrides of the above materials.

As the material of the etching mask film 13, a material including molybdenum (Mo), silicon (Si), tantalum (Ta), hafnium (Hf), aluminum (Al), and titanium use.

When a material containing titanium is used as the material of the etching mask film 13, for example, titanium oxide, titanium nitride, or titanium oxynitride can be used. In this case, as an etching solution used for etching-removing the etching mask film 13, a mixed aqueous solution of potassium oxide and hydrogen peroxide can be used.

Further, as the material of the etching mask film 13, a material containing a metal silicide, that is, a material containing a metal and silicon, may be used. Examples of the metal include transition metals such as molybdenum (Mo), tantalum (Ta), tungsten (W), and titanium (Ti). The metal silicide may also be, for example, a nitride of a metal suicide, an oxide of a metal suicide, a carbide of a metal suicide, an oxynitride of a metal suicide, a carbonitride of a metal suicide, an oxycarbide of a metal suicide or an oxycarbonitride of a metal suicide .

Concretely, as the material of the etching mask film 13, a nitride, an oxide, a carbide, an oxynitride, a carbonitride, an oxycarbide and an oxycarbonitride of molybdenum silicide (MoSi), a nitride, an oxide, , Nitrides, oxides and carbides of titanium nitride, carbonitride, oxycarbide and oxycarbonitride, tungsten silicide (WSi), nitrides, oxides, carbides, oxynitrides, carbonitrides, oxides carbides and oxycarbonitrides and titanium silicides , Oxynitride, carbonitride, oxycarbide, and oxycarbonitride.

As described above, as the material for forming the etching mask film 13, a material containing a metal silicide can be used, and a material not including a metal silicide can be used as mentioned above.

The etching mask film 13 may have a thickness of 1 to 500 angstroms, more preferably 25 to 200 angstroms.

It is preferable that the etching mask film 13 is laminated in contact with the phase shift film 12 described above. The adhesion between the phase shift film 12 and the etching mask film 13 is higher than the adhesion between the phase shift film and the photoresist film in the conventional structure and the penetration of the etching liquid is less likely to occur.

Therefore, when the phase shift film 12 is patterned by wet etching, the side to be etched which is the side surface thereof can be made to be perpendicular to the surface of the transparent substrate 11. By doing so, the optical interference of the inverted phase occurring at the boundary (adjacent portion) between the phase shifting portion 16 and the light projecting portion 17 can sufficiently be generated, and the contrast of the light transmission intensity can be increased. This has the effect of making the resolution and the depth of focus advantageous and causing the CD (line width) control of the final product (display device) to occur uniformly in the plane.

The exposure light transmittance of the etching mask film 13 is not particularly limited in the first photomask 10a. For example, in the laminated state of the phase shift film 12, the etching mask film 13, and the light shield film 14, the light shield 15 may have sufficient light shielding properties.

The amount of phase shift of the exposure light of the etching mask film 13 is also not limited. Therefore, in the first photomask, the etching mask film 13 has a large degree of freedom in selecting the material and film thickness, which is advantageous.

[Light-shielding film (14)]

It is preferable that the light shielding film 14 has sufficient light shielding property (optical density OD3 or more) in the laminated state with the phase shift film 12 and the etching mask film 13. [ It is more preferable that the light shielding film 14 has the same light shielding property as the single film. It is preferable that the light-shielding film 14 has an etching selectivity with respect to the etching mask film 13. That is, with respect to the etching liquid of the light-shielding film 14, the etching mask film 13 is required to have resistance.

As the material of the light-shielding film 14, a material containing Cr is preferably used. The material of the light-shielding film 14 is not limited to chromium, for example, chromium oxide (CrOx), nitride (CrNx), carbide (CrCx), oxynitride (CrOxNy), nitride carbide (CrCxNy), oxidized carbide Or a nitride carbide (CrOxNyCz). Further, the material of the light-shielding film 14 may be any one of chromium carbide, chromium nitride carbide, chromium oxycarbide, or chromium oxynitride carbide.

When a material containing tantalum (Ta) is used for the etching mask film 13, molybdenum silicide can be used as the material of the light-shielding film 14.

The light-shielding film 14 may be provided with an antireflection layer on its surface. In this case, the antireflection layer may be made of any one of chromium oxide, chromium nitride and chromium nitride.

The film thickness of the light-shielding film 14 may be 500 to 2000 Å, more preferably 800 to 1500 Å, and further preferably 900 to 1300 Å.

As the etching liquid for the light-shielding film 14, conventionally known ones can be used without any particular limitation. In the case where the light-shielding film 14 is formed of a material containing chromium, the etching liquid used for the light- 12).

The first photomask 10a has a high chemical resistance and is advantageous because the surface exposed to the surface can be made of a chromium-based film.

&Lt; Second photomask >

Next, a cross-sectional view of the photomask according to the second embodiment is shown on the lower side of Fig. 4 (b). The second photomask 10b is also provided with a photomask blank shown in FIG. 3, for example, in the same manner as the first photomask 10a, and the phase shift film 12, the etching mask film 13, (14). &Lt; / RTI &gt;

In this photomask 10b,

The phase shifting film 12, the etching mask film 13 and the light shielding film 14 are patterned by wet etching on the transparent substrate 11 so that the light shielding portion 15, the phase shifting portion 16, A photomask for manufacturing a display device in which a transfer pattern including a light portion (17) is formed,

The shielding part 15 is formed by laminating the phase shift film 12, the etching mask film 13 and the light shielding film 14 in this order on the transparent substrate,

The phase shift portion 16 is formed by forming the phase shift film 12 and the etching mask film 13 on the transparent substrate,

The transparent portion 17 is formed by exposing the surface of the transparent substrate 11,

The phase shift film 12 is made of a material containing chromium,

The etching mask film 13 is made of a material having etching resistance to the etching liquid of the phase shift film 12,

The phase shifting section 16 and the light projecting section 17 are formed on the same plane as the phase shifting section 16 and the light projecting section 17, And has a phase difference of about 180 degrees with respect to the representative wavelength.

That is, the upper diagram of FIG. 4 (b) is an upper surface of the second photomask 10b. The portion where the patterned light-shielding film 14 (i.e., the light-shielding film pattern 14a) is seen when the photomask 10b is viewed from above constitutes the light-shielding portion 15 in Fig. 4 (b) In addition, the portion where the patterned etching mask film 13 (that is, the etching mask film pattern 13a) is visible (there is a patterned phase shift film 12 (that is, the phase shift film pattern 12a) Thereby constituting the phase shifting portion 16. [ The portion of the transparent substrate 11 that is not covered with any of the phase shift film 12, the etching mask film 13 and the light shielding film 14 constitutes the transparent portion 17.

Here, the difference between the second photomask 10b and the first photomask 10a is the configuration of the phase shifting portion 16. That is, the phase shifting film 12 and the etching mask film 13, which are patterned on the transparent substrate 11, exhibit the function of the phase shifting portion 16 in a laminated state. Therefore, in this laminated state, the phase difference (pair representative wavelength) between the phase shifting portion 16 and the light projecting portion 17 becomes approximately 180 degrees.

The phase shift amount in the phase shift film 12 itself is preferably 160 to 200 degrees. At this time, the phase shift amount of the etching mask film 13 is preferably 1 to 50 degrees.

Further, in the above lamination, the variation width of the phase shift amount in the exposure light having a wavelength of 365 nm (i line) to 436 nm (g line) is preferably within 40 degrees, more preferably within 30 degrees . When the variation width is in this range, a phase reversal effect with respect to the representative wavelength of the exposure light is sufficiently obtained.

The exposure light transmittance is also 2 to 15%, preferably 3 to 8% (pair representative wavelength) in the laminated state of the phase shift portion 16.

The exposure light transmittance of the phase shift film 12 itself is preferably 3 to 20%. The exposure light transmittance of the etching mask film 13 alone is preferably 70 to 99%.

The configuration of the phase shifter 16 may be the same as that of the first photomask 10a except for the above-described points.

The constituent films in any of the first and second photomasks can also be formed by a sputtering method, an ion plating method, or a vapor deposition method. However, from the viewpoint of enhancing the adhesion of the interface between two films, The sputtering method is preferable.

There is no particular limitation on the use of the photomask of the present invention described above. For example, it can be suitably applied to a photomask including a line-and-space pattern for forming a pixel electrode or the like of a display device as a transfer pattern.

It is preferable that the line pattern of the line and space pattern has a light shielding portion having a constant width and a phase shift portion having a constant width adjacent to both sides of the light shielding portion having the constant width.

In the model of simulation used in Fig. 1, the width of each phase shifting portion adjacent to both edges of the light shielding portion of the phase shift masks PSM (A) and PSMTP (A) ) Is R = 1 / 4L. However, the present invention is not limited thereto.

For example, the effect of the present invention is high when 4? Pitch width P <6 (占 퐉) and L? 1.5 (占 퐉) and S? 3.5 (占 퐉).

For a fine line and space pattern having a pitch width P <6 (탆), for example, a line and space pattern having a rim of the phase shift portion 16, such as a phase shift mask PSM (A) From the viewpoint of preventing the resist pattern from being separated in the manufacturing process of the mask, the width of the light-shielding portion 15 indicated by (LR) is preferably 0.6 mu m or more.

According to the examination by the inventors of the present invention, when emphasizing the height of contrast at the time of transfer, it is preferable that L &gt; S in a fine line and space pattern of P < , It was also remarkable. More preferably, R? 0.8 (占 퐉).

Further, as shown in Fig. 5, the transfer pattern can be applied to a case including a hole pattern forming a contact hole. The hole pattern includes arranging a plurality of contact holes with a constant regularity (pitch).

For example, the hole pattern includes a transparent portion 17 having a predetermined diameter, a phase shift portion 16 having a constant width surrounding the transparent portion 17, a light shield portion 15 surrounding the phase shift portion 16 ) (See Figs. 5 (a) and 5 (b)).

Here, the hole diameter (the length of one side in the case of the square, the length of the short side in the case of the rectangle, the diameter in the case of the circle) is 1.5 to 5 (탆), and the phase shifter 16, (Rim width R) of 0.3? R? 1.5 (占 퐉).

The photomask of the present invention has a shielding portion 15 in addition to the transparent portion 17 and the phase shifting portion 16. This contributes to an action of reversing and interfering with the light by the phase shifting portion 16 and further enhancing the contrast of the light intensity distribution of the transmitted light.

On the other hand, a light shielding film may be formed on the photomask in addition to the region of the transfer pattern to form the light shielding portion. This makes it possible to maintain a high reading accuracy of a mark pattern such as an alignment mark. That is, since the mark portion can be formed by combining the light-transmitting portion and the light-shielding portion, the contrast is high.

<Surface to be etched>

The photomask of the present invention or the photomask manufactured by the manufacturing method of the present invention described later can be configured as follows.

The surface to be etched of the phase shift film 12 is exposed at a portion of the transfer pattern adjacent to the transparent portion 17 and the phase shift portion 16,

(Upper surface, lower surface and side surface) corresponding to the upper surface, lower surface, and etched surface (side surface) of the phase shift film 12 satisfy the following conditions, respectively, .

(A) a straight line connecting the contact point of the upper side and the side face and the position of the side face at a position of a height lower by two-third the film thickness of the phase shift film (12) from the upper face, The angle ranges from 85 degrees to 120 degrees,

(B) a first imaginary line passing through the contact between the upper side and the side edge and perpendicular to the main surface of the transparent substrate (11), and a second imaginary line extending from the lower side to the side And a second imaginary line perpendicular to the main surface of the transparent substrate (11) through a position of the transparent substrate (11) is not more than one half of the film thickness.

6 (a) and 6 (b) are graphs showing the relationship between the thickness of the patterned phase shift film 12 and the thickness of the patterned phase shift film 12 in the portion where the transparent portion 17 and the phase shift portion 16 are adjacent to each other, (Side) shape of the etching surface. Here, a section of the phase shift film 12 in a state in which the etched surface is exposed is shown. 6 (a) and 6 (b), the PS and the marked layer are the patterned phase shift film 12, and the layer marked with QZ is the transparent substrate 11.

Here, the upper side, lower side and side face corresponding to the upper face, lower face and etched face of the phase shift film 12 in the cross section of the adjacent portion satisfy the above two conditions (A) and (B) do.

That is, the cross section of the adjacent portion is composed of the upper side, the lower side and the side 23 corresponding to the upper and lower surfaces and the etched surface of the phase shift film 12, respectively. 6, the auxiliary line 21 indicates the position of the upper side corresponding to the upper surface of the phase shift film 12, and the auxiliary line 22 indicates the position of the lower side corresponding to the lower surface of the phase shift film 12 . And the auxiliary line 24 indicates the position of the height that is two thirds lower than the film thickness from the top surface of the phase shift film 12. [ In this case, referring to Fig. 6A, the position 27 of the lateral side at the position of the contact 26 of the upper side and the side edge 23 and the height of the lower side by two thirds of the film thickness T from the upper side is An angle? (Also referred to as a side angle) between the connected straight line and the upper side is within a range of 85 degrees to 120 degrees.

6 (b), the auxiliary line 25 indicates the position of the height of the phase shift film 12 which is one tenth the film thickness from the bottom face. In this case, the first imaginary line 29, which is perpendicular to the main surface of the transparent substrate 11 through the contact 26 of the phase and side edges 23, And the width of the second imaginary line 30 perpendicular to the main surface of the transparent substrate 11 through the position 28 of the lateral side 23 at the height of the tenth of the height (D / T) of the film thickness (D) and the film thickness (T) is 1/2 or less.

In the photomask of the present invention, the shape of the etched surface of the phase shift film 12 satisfies the above conditions. That is, the edge portion of the patterned phase shift film 12 has a cross section perpendicular to or perpendicular to the surface of the transparent substrate 11. From this point, it is possible to obtain a high contrast in the light intensity distribution in which the reversed-phase exposure light interferes at the boundary between the transparent portion 17 and the phase shifting portion 16 and reaches the photoresist film as the object to be transferred . The edge side angle? Of the phase shift portion 16 is smaller than that of the example of FIG. 10 to be described later (because it is close to 90 degrees with respect to the surface of the transparent substrate 11) It is possible to suppress the deviation from the design value and to form a finer pattern.

In contrast, in FIG. 10 showing a cross section of a phase shift film pattern obtained by wet etching a resist pattern as a mask with respect to a phase shift film including chromium, the side angle? Is 173 degrees, the thickness ratio of the bottom width (D / T) was 5.6.

According to the examination by the inventors of the present invention, the etched surface when the chromium-based phase shift film is wet-etched using the photoresist pattern as a mask has a side angle? Of 120 degrees or less, (D / T) to 1/2 or less.

[Manufacturing Method of Photomask]

The present invention includes the following method for manufacturing a photomask for manufacturing a display device.

A manufacturing method of a photomask for manufacturing a display device in which a transfer pattern including a light-shielding portion, a phase shifting portion, and a light-transmitting portion is formed by patterning a phase shift film, an etching mask film, and a light- As a result,

Wherein the shielding portion is formed by laminating the phase shift film, the etching mask film, and the light shielding film in this order on the transparent substrate,

Wherein the phase shifting portion is formed by forming the phase shift film or the phase shift film and the etching mask film on the transparent substrate,

Wherein the transparent portion of the transparent substrate is exposed, the method comprising the steps of:

A step of preparing a photomask blank on which a phase shift film, an etching mask film, and a light shielding film are stacked in this order and on which a first photoresist film is formed,

A step of forming a transfer pattern by subjecting the phase shift film, the etching mask film and the light shielding film to predetermined patterning,

The step of patterning the phase shift film includes wet etching the phase shift film using the patterned etching mask film as a mask,

Wherein the phase shift film is made of a material containing chromium,

The etching mask film is made of a material having an etching resistance to the etching liquid of the phase shift film,

Wherein the phase shifting portion and the light transmitting portion have mutually adjacent portions and the phase shifting portion and the light transmitting portion have a phase difference of about 180 degrees with respect to a representative wavelength of exposure light of the photomask , A method of manufacturing a photomask for manufacturing a display device.

3, the phase shift film 12, the etching mask film 13, and the light shield film 14 are laminated on the transparent substrate 11, and the phase shift film 12, 1 A photomask blank in which a photoresist film 18 is formed is prepared. The film formation of each film may be made, for example, as follows.

Specifically, a chromium-containing phase shift film 12 is formed on the main surface of a transparent substrate 11 (size 330 mm x 450 mm) of synthetic quartz glass by a sputtering method (film forming step). Thereafter, it is preferable to expose the phase shift film 12 to the atmosphere gas to be described later (exposure process) continuously without exposure to the atmosphere.

The phase shift film 12 preferably contains carbon (C) or fluorine (F) in addition to chromium. It is considered that the phase shift film 12 including these elements is effective because the shape of the etched surface is preferably controlled at the time of wet etching.

In the film-forming step, a sputter target containing chromium or a chromium compound is used by a known apparatus to contain an inert gas, an oxygen gas, a nitrogen gas, a nitrogen monoxide gas, a nitrogen dioxide gas, a carbon dioxide gas, A mixed gas with an active gas containing any one of a gas and a fluorine gas may be used. For example, a sputter gas atmosphere containing a carbon dioxide gas, a hydrocarbon gas or a fluorine gas is preferably used. These are effective for controlling (delaying) the wet etching rate of the phase shift film 12.

For example, using a target made of chromium, a mixed gas of argon (Ar) gas, nitrogen (N ₂ ) gas and carbon dioxide (CO ₂ ) gas is introduced into a sputter chamber (not shown) , The phase shift film 12 made of CrCON can be formed on the transparent substrate 11. It is preferable that the formed film is continuously sent to the next step in a gas atmosphere containing an active gas such as a carbon dioxide gas, a hydrocarbon gas or a fluorine gas without touching the atmosphere. An inert gas (helium gas, neon gas, argon gas, krypton gas, xenon gas or the like) may be contained in the gas atmosphere for the exposure, and oxygen gas, nitrogen gas or the like may be included as the active gas.

The phase shift film 12 may be a single layer or a plurality of layers. When the phase shift film 12 is composed of a plurality of layers, the film forming step and the exposing step are performed a plurality of times.

Next, an etching mask film 13 is formed on the phase shift film 12 by a sputtering method. As an example, the formation of the etching mask film 13 containing MoSi will be described below.

A sputter gas (for example, a mixed gas of argon (Ar) gas and nitrogen monoxide (NO) gas) is introduced into a sputter chamber in which molybdenum silicide (for example, Mo: Si = 1: 4) And an etching mask film 13 made of MoSiON is formed on the phase shift film 12 by applying sputtering power.

The surface reflectance of the etching mask film 13 thus formed can be 15% or less (pair representative wavelength).

According to the examination by the inventors of the present invention, the deposition of the phase shift film 12 and the etching mask film 13, which was formed as described above, was analyzed by X-ray photoelectron spectroscopy (XPS) And it can be said that it can have the same preferable tendency. That is, a region where a chromium (Cr) peak attributable to the phase shift film 12 and a silicon (Si) peak (or a molybdenum (Mo) peak) caused by the etching mask film 13 are superimposed , The content of carbon (C) increases stepwise or continuously in the direction of the surface of the etching mask film 13 (toward the direction away from the surface of the transparent substrate 11). Here, since carbon has a function of lowering the wet etching rate of the phase shift film 12, it is necessary to improve the shape of the etched surface of the phase shift film 12 (the cross section of the edge portion of the phase shift film 12 , And to be perpendicular or perpendicular to the surface of the transparent substrate 11].

On the other hand, as the etching mask film 13, for example, an oxynitride film of titanium can be formed by using a sputtering method in which a sputtering method using a target of titanium is applied and oxygen gas and nitrogen gas are introduced. The etching mask film 13 may be a single layer or a plurality of layers.

Next, a light shielding film 14 is formed on the etching mask film 13 by a sputtering method. The light-shielding film 14 also has a function of indirectly improving the adhesion between the etching mask film 13 and the first photoresist film 18 formed on the light-shielding film 14. In this case, when the light shielding film 14 is formed of a material containing chromium, for example, a sputter target containing chromium or a chromium compound may be used to contain an inert gas, and an oxygen gas, a nitrogen gas, a carbon dioxide gas , An oxygen-containing gas, an oxygen-containing gas, a hydrocarbon-based gas, and a fluorine-based gas is sputtered in a sputter gas atmosphere.

After the light-shielding film 14 is formed, the first photoresist film 18 is further applied.

Thus, a photomask blank as shown in Fig. 3 is produced. In the production of the photomask of the present invention, this photomask blank is prepared.

The patterning of the phase shift film 12, the etching mask film 13, and the light shield film 14 may include the following steps.

&Lt; Preparation method 1 >

7 is a diagram showing an example of a method of manufacturing the photomask of the first and second embodiments of the present invention.

First, after the photomask blank is prepared (Fig. 7 (a)),

The first resist pattern 18a is formed by performing drawing and development on the first photoresist film 18 (Fig. 7 (b)),

The light shielding film 14 is wet etched using the first resist pattern 18a as a mask to form a light shielding film pattern 14a (Fig. 7 (c)),

After the first resist pattern 18a is peeled off (Fig. 7 (d)),

A second photoresist film 19 is formed on the entire surface of the transparent substrate 11 on which the light-shielding film pattern 14a is formed (Fig. 7 (e)),

A second resist pattern 19a is formed by drawing and developing the second photoresist film 19 (Fig. 7 (f)),

The etching mask film 13 is wet-etched using the second resist pattern 19a as a mask to form an etching mask film pattern 13a (Fig. 7 (g)),

The phase shift film 12 is wet-etched using the obtained etching mask film pattern 13a as a mask to form the phase shift film pattern 12a (Fig. 7 (h)).

When the second resist pattern 19a is peeled off, the photomask 10b of the second embodiment described above is completed (Fig. 7 (i)).

After that, it is preferable to wet-etch the etching mask film 13 using the formed light-shielding film pattern 14a as a mask. Thereby, the photomask 10a of the first embodiment described above is completed (Fig. 7 (j)).

&Lt; Production method 2 >

8 is a view showing another example of the method of manufacturing the photomask of the first and second embodiments of the present invention. Here, the case where the light-shielding film 14 and the phase shift film 12 are both films containing chromium is shown.

After preparing the photomask blank (Fig. 8 (a)),

The first resist pattern 18a is formed by performing drawing and development on the first photoresist film 18 (FIG. 8 (b)),

The light shielding film 14 is subjected to wet etching using the first resist pattern 18a as a mask and successively wet etching the etching mask film 13 and the phase shift film 12 to form an exposed portion of the transparent substrate 11 The transparent portion 17 is formed (Fig. 8 (c)),

A second photoresist film 19 is formed on the entire surface of the transparent substrate 11 on which the transparent portion 17 is formed (Fig. 8 (d)) after removing the first resist pattern 18a The second resist pattern 19a is formed by drawing and developing the second photoresist film 19 (FIG. 8 (f)),

The light shielding film 14 is wet etched using the second resist pattern 19a as a mask to form a light shielding film pattern 14a (Fig. 8 (g)).

By removing the second resist pattern 19a, the photomask 10b of the second embodiment of the present invention is obtained (FIG. 8 (h)).

After the light-shielding film pattern 14a is formed, the etching mask film 13 is wet-etched using the second resist pattern 19a and the formed light-shielding film pattern 14a as masks to form an etching mask film pattern 13a (Fig. 8 (i)). Thereafter, the second resist pattern 19a is removed to obtain the photomask 10a of the first embodiment of the present invention (Fig. 8 (j)).

&Lt; Preparation method 3 >

9 is a view showing still another example of the method for manufacturing the photomask of the first embodiment of the present invention.

After preparing the photomask blank (Fig. 9 (a)),

The first resist pattern 18a is formed by performing drawing and development on the first photoresist film 18 (Fig. 9 (b)),

The light shielding film 14 is wet-etched by the first etching solution using the first resist pattern 18a as a mask to form a light shielding film pattern 14a (Fig. 9 (c)),

Then, the etching mask film 13 is wet-etched by the second etching solution to form an etching mask film pattern 13a (Fig. 9 (d)),

The phase shift film 12 is wet-etched by the first etching liquid and the light-shielding film pattern 14a is etched side-by-side (FIG. 9 (e)) using the etching mask film pattern 13a as a mask, ,

The etching mask film pattern 13a is again etched by the second etching solution using the light-shielding film pattern 14a having been subjected to the side etching as a mask (Fig. 9 (f)),

Thereafter, the first resist pattern 18a is peeled off (FIG. 9 (9)).

According to this manufacturing method, it is possible to perform drawing and development in one cycle, and it is advantageous in that it is possible to make the influence of the alignment displacement of each other by a plurality of drawing processes zero. Particularly, (Refer to FIG. 9 (f)), which is capable of precisely forming the film.

[Method of transferring pattern and manufacturing method of display device]

The present invention includes a pattern transfer method. That is, the method includes transferring the transfer pattern of the photomask using the photomask and the exposure apparatus described above.

The present invention also includes a method of manufacturing a display device including pattern transfer using the photomask and the exposure apparatus described above.

That is,

A step of preparing a photomask for manufacturing a display device of the present invention and a step of forming a transfer pattern provided in the photomask using an exposure apparatus for manufacturing a display device which irradiates exposure light including i-line, h-line and g- And transferring the transfer pattern onto a transfer target body.

The present invention also provides a method for manufacturing a display device, comprising the steps of preparing a photomask for manufacturing a display device of the present invention, and exposing the exposure light including i-line, h-line and g- And transferring the transfer pattern onto the transfer target body by exposing the transferred transfer pattern to the transfer target pattern.

The exposure apparatus to be used may be a standard exposure apparatus for equal exposure for LCD. That is, by using a light source of a wavelength range including an i-line, an h-line, and a g-line (also referred to as a broad wavelength light source), a sufficient irradiation light amount can be obtained. However, only light of a specific wavelength (for example, i-line) may be used by using an optical filter.

The optical system of the exposure apparatus may have a numerical aperture NA of 0.06 to 0.10 and a coherence factor (sigma) of 0.5 to 1.0. Such an exposure apparatus generally has a resolution limit of about 3 mu m.

Of course, the present invention can also be applied to the case of transfer using a wider range of exposure apparatuses. For example, the NA may be in the range of 0.06 to 0.14, or 0.06 to 0.15. There is also a demand for a high-resolution exposure apparatus in which the NA exceeds 0.08, and the present invention can be applied to these.

As is apparent from the above, the photomask of the present invention has the surface to be etched of the phase shift film perpendicular to the transparent substrate, so that it is possible to improve the profile of the shape of the photoresist pattern on the surface to be obtained by exposure It became possible.

[Example]

According to the examination by the present inventors, in the following photomask for manufacturing a display device manufactured using the above production method 1, the boundary between the transparent portion of the transfer pattern and the phase shift portion (the exposed surface of the phase shift film is exposed) , And 9 arbitrary points were inspected within the plane. That is, the portion where the side angle? And the thickness ratio D / T of the bottom width are measured and the side angle? Are in the range of 100 to 105 degrees and the film thickness ratio (D / T) (In the range of 0.40 to 0.45).

(Photomask according to the first embodiment)

Transparent substrate: Synthetic quartz glass size (330 mm x 450 mm)

The formed pattern: a line width of 3 mu m, a space width of 3 mu m, a line-and-space pattern of 0.5 mu m per phase shift portion (rim width)

Phase shift film: CrOCN film thickness 1200 Å

Exposure light transmittance (pair i-line): 6%

Phase difference (pair i-line): 180 degrees

Etching mask film: MoSiON film thickness 100 Å

Shielding film (having an antireflective layer): CrOCN / CrC / CrON film thickness 1000 Å optical density (OD) ≥3

The present invention has been described above with reference to a plurality of modes, but the present invention is not limited to the above modes. The constitution and details of the present invention can be modified in various manners within the spirit and scope of the present invention as will be understood by those skilled in the art.

2a, 2b, 2c: line pattern
3a, 3b, 3c: Space pattern
10a, 10b: photomask
11: transparent substrate
12: phase shift film
12a: phase shift film pattern
13: etching mask film
13a: etching mask film pattern
14:
14a: a light-shielding film pattern
15:
16: phase shift unit
17:
18: First photoresist film
18a: first resist pattern
19: Second photoresist film
19a: second resist pattern
101: transparent glass substrate
102: phase shift film pattern
103: Resist pattern

Claims (9)

A photomask for manufacturing a display device in which a transfer pattern including a light-shielding portion, a phase shifting portion, and a light-transmitting portion is formed by patterning a phase shift film, an etching mask film, and a light-
Wherein the shielding portion is formed by stacking the phase shift film, the etching mask film, and the light shielding film in this order on the transparent substrate,
Wherein the phase shift portion is formed by forming the phase shift film or the phase shift film and the etching mask film on the transparent substrate,
Wherein the transparent portion is formed by exposing the surface of the transparent substrate,
Wherein the phase shift film is made of a material containing chromium,
Wherein the etching mask film is made of a material having an etching resistance to an etching liquid of the phase shift film,
The phase shifting portion and the light transmitting portion have portions adjacent to each other and the phase shifting portion and the light transmitting portion have a phase difference of about 180 degrees with respect to the representative wavelength of the exposure light of the photomask
Photomask for manufacturing display devices. The method according to claim 1,
Wherein the transfer pattern includes a line and space pattern,
The line pattern of the line-and-
A light shielding portion having a constant width,
And a phase shift portion having a constant width adjacent to both sides of the light shielding portion of the constant width. The method according to claim 1,
Wherein the transfer pattern includes a hole pattern,
Wherein the hole pattern has a transparent portion having a predetermined diameter, a phase shift portion having a constant width surrounding the transparent portion, and a shielding portion surrounding the phase shift portion. 4. The method according to any one of claims 1 to 3,
Wherein the phase shift portion includes the phase shift film formed on the transparent substrate,
Wherein the phase shift film is phase shifted approximately 180 degrees with respect to a representative wavelength of the exposure light. 4. The method according to any one of claims 1 to 3,
Wherein the phase shift portion is formed by stacking the phase shift film and the etching mask film in this order on the transparent substrate,
Wherein the stacking of the phase shift film and the etching mask film shifts phase by about 180 degrees with respect to a representative wavelength of the exposure light. 4. The method according to any one of claims 1 to 3,
Wherein the surface to be etched of the phase shift film is exposed at portions where the transparent portion and the phase shift portion are adjacent to each other in the transfer pattern,
(A) - a contact point between the upper side and the side face, and a phase difference between the upper side, the lower side, and the side surface corresponding to the upper surface, the lower surface, and the side surface to be etched, Wherein the straight line connecting the position of the side edge at a position where the height of the shift film is two thirds lower than the film thickness is within a range of 85 degrees to 120 degrees with respect to the upper side; and Condition (B) Through the contact of the transparent substrate and the position of the lateral side at a position which is one-tenth the height of the film thickness from the bottom, and a second imaginary line perpendicular to the main surface of the transparent substrate And a second imaginary line perpendicular to the surface is equal to or smaller than half of the film thickness. A phase shift film, an etching mask film, and a light shielding film are patterned by wet etching, respectively, on a transparent substrate to form a transfer pattern including a light-shielding portion, a phase shifting portion, and a light transmitting portion,
Wherein the shielding portion is formed by stacking the phase shift film, the etching mask film, and the light shielding film in this order on the transparent substrate,
Wherein the phase shifting portion is formed by forming the phase shift film or the phase shift film and the etching mask film on the transparent substrate,
Wherein the transparent portion of the transparent substrate is exposed, the method comprising the steps of:
A step of preparing a photomask blank in which a phase shift film, an etching mask film and a light shielding film are laminated in this order on the transparent substrate and a first photoresist film is formed,
A step of forming a transfer pattern by subjecting the phase shift film, the etching mask film and the light shielding film to predetermined patterning,
The step of patterning the phase shift film includes wet etching the phase shift film using the patterned etching mask film as a mask,
Wherein the phase shift film is made of a material containing chromium,
The etching mask film is made of a material having an etching resistance to the etching liquid of the phase shift film,
Wherein the phase shifting portion and the light transmitting portion have portions adjacent to each other and the phase shifting portion and the light transmitting portion have a phase difference of about 180 degrees with respect to a representative wavelength of the exposure light of the photomask
A method of manufacturing a photomask for manufacturing a display device. A method for manufacturing a display device, comprising the steps of: preparing a photomask for manufacturing a display device according to any one of claims 1 to 3;
a step of exposing a transfer pattern provided in the photomask using an exposure apparatus for manufacturing a display device which irradiates exposure light including i line, h line and g line, and transferring the transfer pattern onto the transfer target body Containing pattern transfer method. A method for manufacturing a display device, comprising the steps of: preparing a photomask for manufacturing a display device according to any one of claims 1 to 3;
a step of exposing a transfer pattern provided in the photomask using an exposure apparatus for manufacturing a display device which irradiates exposure light including i line, h line and g line, and transferring the transfer pattern onto the transfer target body Wherein the method comprises the steps of:

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